MoonLake Immunotherapeutics reported positive Phase 2 results for sonelokimab, a subcutaneous IL‑17 nanobody, achieving the primary ASAS40 endpoint in patients with axial spondyloarthritis (axSpA). The trial showed an 81% ASAS40 response at week 12 and imaging (PET and MRI) and biomarker data indicating reduced joint inflammation and osteoblast activity. MoonLake emphasized sonelokimab’s tissue accessibility and biomarker effects as evidence of mechanism; PET imaging demonstrated decreased sacroiliac joint inflammation, a driver of irreversible ossification. The company said the data support confidence ahead of regulatory filings and further development, noting potential advantages of nanobody formats for manufacturing and tissue penetration.